title: Ir gene function in an I-A subregion mutant B6.C-H-2bm12.
abstract: The B6.C-H2bm12 (bm 12) strain has a mutation in the I-A subregion of the murine H-2 complex and is characterized by a loss of serologically detected Ia antigens and a strong graft rejection and mixed lymphocyte response between parent and mutant. It was presumed that the mutation affected the Ia-1 gene and to determine the relationship of Ia antigens and Ir genes, the immune responses of mutant and parent were compared. The immune responses to poly(L-Tyr,LGlu)-poly(DLAla)--poly(LLys), poly(Phe,Glu)-poly(DLAla)--poly(LLys), and poly(His,Glu)-poly(DLAla)--poly(LLys) in parent and mutant were same, indicating the Ia-1 and the Ir genes for these antigens are not identical. By contrast, although C57BL/6 gave a good response, the mutant strain was unable to generate cytotoxic T lymphocytes to the male-specific H-Y antigen--a response under I-A subregion Ir gene control, which now must be considered to be the Ia-1 gene. In addition, complementary Ir genes in the H-2b haplotype for the H-Y immune response could be detected when the bm12 mutant was used.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D003602:Cytotoxicity, Immunologic; D005260:Female; D005802:Genes, MHC Class II; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains / Q000235:genetics*; D010455:Peptides / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000949:Histocompatibility Antigens Class II; D010455:Peptides; C021759:(T,G)-A-L